The present invention relates to liquid propellant guns and particularly to an injector assembly therefor. The invention has for an object thereof the prevention of back pressure on the injector mechanism.
Previous designs, for example, have subjected the injection mechanism to firing pressures. To survive firing, these components had to be small. This limited the propellant flow areas, slowing injection and rate of fire. Additionally, flow passages were left exposed, allowing ullage, unburned propellant, and structural weakening. Guns of this type have been known to fail by hot gas leakage into the injector mechanism often with resulting spontaneous disassembly.
The present invention is an improvement over the prior liquid propellant gun design disclosed in Assignee's prior application Ser. No. 612,817 filed Sept. 12, 1975 and identified as Navy Case No. 57678.
The design in assignee's prior application referenced above protects the injector mechanism by advancing the bolt to block the firing pressure. In other words, after injection, the bolt is moved forward translating the projectile, propellant charge, and bolt mechanism down bore until the end of the bolt is ahead of the injector. The bolt mechanism must then stop and lock the gun before firing. This protects the injector, but the bolt actuation and locking system is complicated and must be heavy enough to withstand firing pressures. Power requirements are high and the rate of fire is reduced as a consequence of the stop-start action.